Gas spring

The invention relates to a gas spring which uses a compensating medium acting on a compensating piston in order to compensate the dependence on temperature of its characteristic. According to a first aspect of the invention, a compensating medium ( 16 M) is selected whereof the critical temperature (TK) is between the lower limit temperature (Tlower) and a temperature exceeding the upper limit temperature (Tupper) of the range of operating temperatures of the gas spring ( 50 ) by up to 100° C., and the gas spring ( 50 ) is designed such that, at an operating temperature (TB) of the gas spring ( 50 ) not exceeding the critical temperature (TK) of the compensating medium ( 16 M), the point indicating the state of the compensating medium ( 16 M) lies on or above the vapor pressure curve. According to a second aspect, in order to simplify the structure of the gas spring ( 50 ), a single compensating piston ( 10 ) which takes the shape of a cup is used and separates the working chamber ( 1 a), the compensating chamber ( 16 ) and the restoring chamber ( 15 ) of the gas spring ( 50 ) from one another.